libcfg+ is a C library that features multi- command line and configuration 
file parsing. It is possible to set up various special properties such as 
quoting characters, deliminator strings, file comment prefixes, multi-line 
postfixes, and more. It supports many data types such as booleans, integers, 
decimal numbers, strings with many additional data type flags (such as 
multiple values for a single option).

WWW: http://platon.sk/projects/libcfg+